u sure? cmmd-panthers concentrated fire is 45munitions (not 80 like mark vehicle) and is supposed to buff accuracy not damage... ive read various claims that it buffs dmg by 50%... yet the ability description says otherwise.
It actually does do slightly more damage to the marked target. Unless it underwent a ninja change...
I did test the command panther on IS-2's and the IS-2 definitely took more damage when marked.
But the command panther itself can only mark, and i believe that ability has a radius.